1. Field of the Invention
The present invention relates generally to a TV lens operating unit, and more particularly to a TV lens operating unit in which a quick zooming function is installed.
2. Description of Related Art
In an electronic news gathering (ENG) camera, a lens drive unit is attached to the side of a lens barrel. A zoom drive motor and an iris drive motor are arranged in the drive unit. Switch members, provided to the drive unit, are operated and the motors are driven, thereby a zoom ring and an iris ring of the lens barrel are rotated by the motors.
Conventionally, a drive unit, installed with a function called quick zooming, is known. In the quick zooming function, pressing an operation button (hereinafter referred to as a quick zoom switch) rotates the zoom ring to a telephoto side so as to successively move the zoom ring to the telephoto side, and releasing the quick zoom switch causes the zoom ring to rotate to the widephoto side so as to return the zoom to its original position. Japanese Patent Application No. 9-315651 discloses a drive unit in which a quick zooming function is installed. The drive unit prevents a problem, which happens when the quick zoom switch is mistakenly operated during a normal zooming operation; and the maximum zoom rate at normal zooming operation can be set independently of a zoom rate at quick zooming.
In case of TV shooting in a studio and outdoor sport broadcast, generally a TV lens called an electronic field production (EFP) lens is used. The EFP lens is constructed differently from the above-mentioned ENG lens in that the EFP lens has a built-in motor for driving the lens, and the motor is driven and controlled based on a control signal input from an outside controller. However, up to this present time, no EFP lens has ever had a quick zooming function. Consequently, there was nothing suggested for positions of operation buttons and a circuit arrangement and so forth of the conventional EFP lens with the quick zooming function.
Moreover, a moving direction of a zoom by quick zooming was in many cases fixed to either a widephoto side or a telephoto side; in the majority of cases was the telephoto side. However, there are many cases to use the zoom at the telephoto side in sport broadcast for instance; in this case it would be necessary to perform quick zooming to the widephoto side in order to instantly view the whole scene.
The present invention has been developed in view of the above-described circumstances, and has as its object the provision of a TV lens operating unit which drives and controls built-in motors based on control signals transmitted from an outside controller and moves a focus lens and a variable lens by driving the motors; wherein a preferable zooming operation can be performed with a quick zooming function.
In order to achieve the above-described object, the present invention is directed to a TV lens operating unit for operating a TV lens including a focus lens and a variable lens moved in accordance with control signals sent from the TV lens operating unit, the TV lens operating unit comprising: an operating member for ordering, by a one-touch operation thereof, the TV lens to perform a quick zooming wherein the variable lens is successively moved in one of a direction of a widephoto side and a direction of a telephoto side.
The TV lens operating unit further comprises: a focus demand for outputting the control signal to move the focus lens; and a zoom demand for outputting the control signal to move the variable lens; wherein the operating member is provided to one of the focus demand and the zoom demand.
The TV lens operating unit further comprises a switch for selecting a moving direction of the variable lens on the quick zooming from the directions of the widephoto side and the telephoto side.
The TV lens may comprise a switch for selecting a moving direction of the variable lens on the quick zooming from the directions of the widephoto side and the telephoto side.
The operating member may comprise a first operating member for moving the variable lens in the direction of the widephoto side and a second operating member for moving the variable lens in the direction of the telephoto side.
According to the present invention, the quick zooming is easy to perform since the operating member for the quick zooming is provided to the controller that performs focusing and zoom adjustment.
In addition, the quick zooming function can be used more effectively than conventional one because the moving direction of the zoom with the quick zooming is selected by the switch, and the quick zooming can be performed to the widephoto side or the telephoto side according to a shooting condition.